Internal combustion engine



July 14, 1936. v A. KREUZER 2,047,785

INTERNAL COMBUSTION ENGINE Filed July 22, 1933 y aw W \T HIE Patented July 14, 19 36 PA ENT OFFiCE' 2,047,785 INTERNAL COMBUSTION ENGINE Alois Kreuzer, Augsburg, Germany, assignor to Maschinenfabrilr Augsburg-Niimberg A. G., Augsburg, Germany, a corporation of Germany Application July 22, 1933, Serial No. 681,723 in Germany August 25, 1932 4 illaims. (Cl. 123-611) This invention relates to internal combustion engines and more particularly to engines in which there is a stream of air' or the like entering the cylinder-with an unbalanced cooling effect of the pistonrod.

In double-acting, two-cycle Diesel engines, for examplain which the scavenging air enters the cylinder through an opening in the cylinder wall and flows in the general direction of the piston rod, the scavenging air meets only those portions of the piston rod adjacent the piston which are facing the entrance ducts. The portion of the piston rod which is exposed to the scavenging air is therefore more effectively cooled during the time of scavenging air flow than the other side of the piston rod, which is not exposed to the scavenging air current. The heat ab sorption of the piston rod, however, is almost uniform during the time of combustion, as the injection nozzles are usually arranged symmetrically in the combustion chamber. Due to the even heat absorptionat the time of combustion and the uneven cooling eiiect of the scavenging air, there is a differen ce in the average temperature of the sides of the piston rod which in time produces a bend in the rod and causes the piston itself to assume a one-sided position productive of unusual wear of oneside of the cylinder and'piston. The piston rod stufiing box is also unevenly stressed and excessively worn by the bent piston rod. Eventually the extremely unfavorable stressing of the piston rod due to its bend may result in breakage of the rod.

The object of the present invention isto overcome the defects and disadvantages of the prior constructions as above outlined. More effective heating of that portion of the piston rod end which obtains the greatest cooling efiect from the scavenging air entering the cylinder is therefore provided.

Other objects and advantages of the inventio will be apparentlfrom the following description, the appended. claims and the accompanying drawing, in. which- Fig. 1 is a central vertical sectior'rof the lower portion of a two-cycle double-acting engine cylinder, embodying the present invention; and- Fig. 2 is a transverse section on the line l of Fig. 1.

Referring more particularly to the drawing by reference letters, a designates the lower portion of the cylinder of a double-acting engine. In accordance with the preferred embodiment of the invention, the engine is of the two-stroke full line position as shown in Fig. 1.

double-acting Diesel typeoperating with scavenging air.

Within the engine cylinder (1 is the piston c. Secured to the piston is a piston rod d extending slidably through the piston rod stufiing box i provided in the head or cylinder end b. Suitable fuel injectionnozzles may be arranged symmetrically in the end head b in any customary manner.

Arranged in the cylinder in such a way as to unevenly shield the portion of the piston rod which remains permanently in the combustion chamber is a protective member g; preferably a sleeve one side of which is cut away as indicated at h. When the piston is at the start of a piston stroke, and in the dotted line position shown in Fig. 1, the protective shield 9 extends from the end head I) substantially to the lower side of the piston and shields or covers that side of the piston rod which faces away from the flow of scavenging air that obtains through scaveng-' ing air inlet ports e when the piston is in its With the piston in its full line position indicated, the scavenging air flow entering through the inwardly directed ports e which are uncovered by the piston, flows toward and past the piston rod and then sweeps down, around and up again before passing out the outlet parts I. As the cool flow of air strikes the right-hand side of the piston rod at the point It it tends to cool that side considerably more than the other. The shield member 9! is, therefore so arranged as to expose that side of the piston rod which faces the inlet ports e so that at the time the fuel is injected and combustion takes place there will be a greater heating effect on this exposed portion, and the greater cooling efiect that obtains by reason of the scavenging air flow will produce a balance of temperature and a balance of expansion effects and strains. The heat expansion eiiect in the various portions of the piston rod is therefore substantially uniform over the entire piston rod periphery, and the piston rod therefore effectively maintains its normal straight character over long periods of time.

Attention is directed to the fact that the protective shield or sleeve g must unevenly expose that portion of the piston rod remaining permanently in the cylinder at the time of combustion.

If the shield fully surrounded and enclosed the entire piston rod end the heat absorption effect at the time of combustion would be balanced or even while the cooling eifect produced by the scavenging air would be unbalanced or uneven is fixed with respect to the cylinder end head b and with respect to" the stufilng box ring i. It may be secured directly to the inner end of the stufiing box ring 1' as shown in the drawing, or may be attached to the end head b directly or to the piston or piston rod. It is preferred however to attach it to an engine part that is cooled by the cooling jacket provided around the engine cylinder for example as there is thus a more eflective heat removal and a better protection or shielding eifect is obtained.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in theappended claims.

What is claimed is:

1. In an engine of the" character described, an engine cylinder having a transversely extending end head and having an opening in the cylinder wall through which air enters the cylinder, a piston operating in said cylinder, a piston rod fixed to the piston and operating through said end head, the construction being such that one side of the piston rod is cooled to a greater degree than the other side thereof by the air entering the cylinder through said opening, and a member fixed with relation to said end head and projecting into the combustion chamber so as to shield one side of the portion of the piston rod which remains in the combustion chamber at the start of the piston stroke and providing for more effective heating of the side of the piston rod which obtains the greatest cooling effect from the air entering the cylinder through said opening.

2. In a double-acting two-cycle Diesel engine, an engine cylinder having an end head, and having an opening in the cylinder wall through which scavenging air enters the cylinder, a piston operating in said cylinder, a piston rod fixed to the piston, the construction being such that one side of the piston rod near the piston is cooled to a greater degree than the other side thereof by the scavenging air entering the cylinder, a bushing fixed in said end head and slidably receiving said piston rod, and a protective member fixed to said bushing and projecting into the combustion chamber so as to provide for exposure of said one side but shielding the-said other side of that portion ofv the piston rod which remains in the combustion chamber at the start of the piston stroke and providing for more, effective heating of the side portion of the piston rod which obtains the greatest cooling effect from the scavenging air entering the cylinder.

3. In an engine, an engine cylinder having an 10 end head and having a piston controlled scavenging air inlet opening in one side of the cylinder is at the end of the power stroke, and a protective member provided within the combustion chamber and providing for exposure of said one side of the piston rod but enclosing the other side of that portion of the piston rod which remains in the combustion chamber at the start of the piston stroke, so as to provide for more eiiective heating of the side of the piston rod which obtains the greatest cooling eifect from the air entering the cylinder through said opening.

4. In a double acting two-cycle engine of the character described, an engine cylinder having an end .head extending substantially transversely across the cylinder end and having a scavenging air inlet opening in one side of the cylinder wall adjacent the piston head when the piston is at the end of the power stroke, a piston operating in said cylinder, 9. piston rodfixed to the piston and operating through said end head, said air inlet opening being arranged to direct scavenging air unsymmetrically towards said piston rod so that one side of the piston rod is cooled to a greater degree than the other side thereof when the pis- V ton is at the end of the power stroke, anda stationary member providing for exposure of said one side of said piston rod but enclosing the other side of that portion of the piston rod which remains in the combustion chamber at the start of the piston stroke. 7

ALOIB KREUZER. 

